From b55102826d7d3d41a5777931689c746207308c95 Mon Sep 17 00:00:00 2001 From: Boris Burkov Date: Thu, 21 Aug 2025 14:55:37 -0700 Subject: [PATCH] btrfs: set AS_KERNEL_FILE on the btree_inode extent_buffers are global and shared so their pages should not belong to any particular cgroup (currently whichever cgroups happens to allocate the extent_buffer). Btrfs tree operations should not arbitrarily block on cgroup reclaim or have the shared extent_buffer pages on a cgroup's reclaim lists. Link: https://lkml.kernel.org/r/2ee99832619a3fdfe80bf4dc9760278662d2d746.1755812945.git.boris@bur.io Signed-off-by: Boris Burkov Acked-by: Shakeel Butt Tested-by: syzbot@syzkaller.appspotmail.com Cc: Johannes Weiner Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Muchun Song Cc: Qu Wenruo Cc: Roman Gushchin Signed-off-by: Andrew Morton --- fs/btrfs/disk-io.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 70fc4e7cc5a0e..7fab5057cf8e9 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1930,6 +1930,7 @@ static int btrfs_init_btree_inode(struct super_block *sb) BTRFS_I(inode)->root = btrfs_grab_root(fs_info->tree_root); set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); __insert_inode_hash(inode, hash); + set_bit(AS_KERNEL_FILE, &inode->i_mapping->flags); fs_info->btree_inode = inode; return 0; -- 2.47.3